Scuba Hand Signals

Why signals matter

With a regulator in your mouth, divers can't talk. Hand signals let you check on your buddy, point out marine life, agree when to turn the dive and, most importantly, ask for help. Most signals are taught in entry-level courses and are widely understood, but details vary between agencies, countries and dive centres. That's why every dive briefing should review the signals the group will use, and why buddies should agree them during the buddy check.

Signals for asking and answering

• OK? / OK: touch the tip of your thumb to the tip of your index finger to make a circle, with the other fingers straight. Used as both a question and an answer. Always answer an "OK?" signal.
• Not OK / problem: hold your hand flat, palm down, and rock it from side to side, then point to the source of the problem, such as your ear.
• Stop / hold: hold up a flat hand, palm facing your buddy, or make a fist.
• Look: point two fingers at your eyes, then point at what you want your buddy to see.

Direction signals

• Go up / ascend: thumbs up. This is the most important difference from everyday life: underwater, thumbs up means "let's go up", not "good".
• Go down / descend: thumbs down.
• Level off / stay at this depth: hold your hand flat, palm down, and move it slowly side to side.
• This way: point in the direction to go.
• Slow down: a flat hand moving slowly downward.

Air signals

• How much gas do you have?: tap your pressure gauge or show your open palm with a questioning gesture. Answers are often given with finger numbers for pressure.
• Low on gas: a fist held against your chest. It means it's time to turn the dive and head up together.
• Out of gas: a flat hand moving across your throat like a slicing motion. It's an emergency: your buddy should give you their alternate air source at once.
• Share air: point to your mouth or your buddy's alternate air source, as covered in scuba regulator.

Surface signals

• OK at the surface: make a large circle with one arm curved over your head, fingertips touching the top of your head, or both arms forming a circle. It's big enough to be seen from a boat.
• Help at the surface: wave one arm from side to side above your head.

Signals at night

On a night dive, divers shine their light on their own hand so their buddy can see the signal, never into their buddy's eyes. Lights are also used to signal: a slow circle means "OK", and a fast side-to-side sweep means "attention" or "problem".

Other ways to communicate

Many divers carry a small writing slate for more complex messages. A tank banger or a shaker makes a sound to get attention, though, as explained in light and color underwater, it can be hard to tell where a sound is coming from.

Frequently asked questions